1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
24 */
25 /*
26 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
27 * Use is subject to license terms.
28 */
29
30 #pragma weak llrintl = __llrintl
31 #if defined(__sparcv9) || defined(__amd64)
32 #pragma weak lrintl = __llrintl
33 #pragma weak __lrintl = __llrintl
34 #endif
35
36 #include "libm.h"
37
38 #if defined(__sparc)
39
40 #include "fma.h"
41 #include "fenv_inlines.h"
42
43 long long
44 llrintl(long double x) {
45 union {
46 unsigned i[4];
47 long double q;
48 } xx;
49 union {
50 unsigned i[2];
51 long long l;
52 } zz;
53 union {
54 unsigned i;
55 float f;
56 } tt;
57 unsigned int hx, sx, frac, fsr;
58 int rm, j;
59 volatile float dummy;
60
61 xx.q = x;
62 sx = xx.i[0] & 0x80000000;
63 hx = xx.i[0] & ~0x80000000;
64
65 /* handle trivial cases */
66 if (hx > 0x403e0000) { /* |x| > 2^63 + ... or x is nan */
67 /* convert an out-of-range float */
68 tt.i = sx | 0x7f000000;
69 return ((long long) tt.f);
70 } else if ((hx | xx.i[1] | xx.i[2] | xx.i[3]) == 0) /* x is zero */
71 return (0LL);
72
73 /* get the rounding mode */
74 __fenv_getfsr32(&fsr);
75 rm = fsr >> 30;
76
77 /* flip the sense of directed roundings if x is negative */
78 if (sx)
79 rm ^= rm >> 1;
80
81 /* handle |x| < 1 */
82 if (hx < 0x3fff0000) {
83 dummy = 1.0e30f; /* x is nonzero, so raise inexact */
84 dummy += 1.0e-30f;
85 if (rm == FSR_RP || (rm == FSR_RN && (hx >= 0x3ffe0000 &&
86 ((hx & 0xffff) | xx.i[1] | xx.i[2] | xx.i[3]))))
87 return (sx ? -1LL : 1LL);
88 return (0LL);
89 }
90
91 /* extract the integer and fractional parts of x */
92 j = 0x406f - (hx >> 16);
93 xx.i[0] = 0x10000 | (xx.i[0] & 0xffff);
94 if (j >= 96) {
95 zz.i[0] = 0;
96 zz.i[1] = xx.i[0] >> (j - 96);
97 frac = ((xx.i[0] << 1) << (127 - j)) | (xx.i[1] >> (j - 96));
98 if (((xx.i[1] << 1) << (127 - j)) | xx.i[2] | xx.i[3])
99 frac |= 1;
100 } else if (j >= 64) {
101 zz.i[0] = xx.i[0] >> (j - 64);
102 zz.i[1] = ((xx.i[0] << 1) << (95 - j)) | (xx.i[1] >> (j - 64));
103 frac = ((xx.i[1] << 1) << (95 - j)) | (xx.i[2] >> (j - 64));
104 if (((xx.i[2] << 1) << (95 - j)) | xx.i[3])
105 frac |= 1;
106 } else {
107 zz.i[0] = ((xx.i[0] << 1) << (63 - j)) | (xx.i[1] >> (j - 32));
108 zz.i[1] = ((xx.i[1] << 1) << (63 - j)) | (xx.i[2] >> (j - 32));
109 frac = ((xx.i[2] << 1) << (63 - j)) | (xx.i[3] >> (j - 32));
110 if ((xx.i[3] << 1) << (63 - j))
111 frac |= 1;
112 }
113
114 /* round */
115 if (frac && (rm == FSR_RP || (rm == FSR_RN && (frac > 0x80000000u ||
116 (frac == 0x80000000 && (zz.i[1] & 1)))))) {
117 if (++zz.i[1] == 0)
118 zz.i[0]++;
119 }
120
121 /* check for result out of range (note that z is |x| at this point) */
122 if (zz.i[0] > 0x80000000u || (zz.i[0] == 0x80000000 && (zz.i[1] ||
123 !sx))) {
124 tt.i = sx | 0x7f000000;
125 return ((long long) tt.f);
126 }
127
128 /* raise inexact if need be */
129 if (frac) {
130 dummy = 1.0e30F;
131 dummy += 1.0e-30F;
132 }
133
134 /* negate result if need be */
135 if (sx) {
136 zz.i[0] = ~zz.i[0];
137 zz.i[1] = -zz.i[1];
138 if (zz.i[1] == 0)
139 zz.i[0]++;
140 }
141 return (zz.l);
142 }
143 #elif defined(__x86)
144 long long
145 llrintl(long double x) {
146 /*
147 * Note: The following code works on x86 (in the default rounding
148 * precision mode), but one ought to just use the fistpll instruction
149 * instead.
150 */
151 union {
152 unsigned i[3];
153 long double e;
154 } xx, yy;
155 int ex;
156
157 xx.e = x;
158 ex = xx.i[2] & 0x7fff;
159
160 if (ex < 0x403e) { /* |x| < 2^63 */
161 /* add and subtract a power of two to round x to an integer */
162 yy.i[2] = (xx.i[2] & 0x8000) | 0x403e;
163 yy.i[1] = 0x80000000;
164 yy.i[0] = 0;
165 x = (x + yy.e) - yy.e;
166 }
167
168 /* now x is nan, inf, or integral */
169 return ((long long) x);
170 }
171 #else
172 #error Unknown architecture
173 #endif